How to choose length that would be my ?
Great question. There are two "rules". One is the "old rule of thumb"--4" shorter for recurves, 3" shorter for longbows. The other is AMO, which states 3" shorter, period.
Which one is right? Depends. On some bows one, on some the other, and on some neither one. The only safe bet is to measure an existing string that puts the bow at the proper brace. If you don't have one, make a single loops string and tie a timber hitch in the other end to make a string to measure.
If someone were to decide to use FF on their old Bear, would you explain how to build a string that would be safe...or would you not even entertain the thought?
I won't do it myself--all the old bows I have mean too much to me. If I were to try it, I'd put extra padding in the loops and only use a Flemish string.
What's the difference between all them dang number soup string materials?
Mostly the grade of HMPE used. Dynaflight '97 is SK75; Dynaflight 10 was SK78; 8125 is SK75; 8190 is SK90. 450+, 452X, and Trophy are SK75 and Vectran; BCY-X is 83% SK90 and 17% Vectran.
For practical purposes, all you really need to know is BCY-X is the shizzle. If you prefer a 100% HMPE material, 8190 or 8125 or, in a larger diameter strand, Dynaflight '97.
I've always wanted to learn how to properly pad a string and get my loops made better in a flemish string. It always seems like my bottom loop is about correct, but the top always seems so much bigger.
Padding loops is easy--don't over-think it. Just wax the strands and lay them in, then make the string as usual. If you make it to a tournament I go to, I'll be happy to show you. I plan to be at Compton's this year, plus lots more. I plan to put up a list of shows and tournaments I'll be at in 2014 on my site before long.